Machines for treating loose products are known, for example to perform sterilization or washing treatments on closing stoppers of test tubes for laboratory analyses, small instruments or objects used in operating theatres or laboratories.
Within the field of sterilization, it is known to sterilize the loose products in sterilization machines provided with an airtight chamber in which a rotary drum receives the products to be sterilized on a loading side, or “dirty” side; it then sterilizes the products during a treatment cycle that normally lasts between one and five hours, and then discharges them on a discharge side or “sterile” side, so they can be packaged.
The rotary drums are typically divided up into sectors, or baskets, each containing a predefined quantity of loose products to be loaded into packages after sterilization.
The discharge operations provide to position one of the sectors on each occasion in proximity to a discharge aperture provided in correspondence with the discharge side of the airtight chamber, and then to discharge the loose products present in the sector.
A conveyor body is typically attached to the discharge aperture with a first end; the conveyor body defines a conveyor compartment to direct the loose products that are discharged from the baskets toward the package where they are collected.
The conveyor body is provided with a second end, opposite the first end, having a collection aperture in correspondence with which the package is attached in order to collect the loose products.
The collection aperture is usually made in a plate or wall positioned to close the conveyor compartment.
The conveyor body is also provided with an opening/closing member, configured to selectively open or close the collection aperture. The opening/closing member guarantees the airtight seal of the chamber during the sterilization process, and allows to discharge the loose products from the chamber once the sterilization process is terminated.
One disadvantage of this known solution is that during the discharge operations some loose products can position themselves stably in dead zones of the conveyor compartment, for example in correspondence with the plate where there is the collection aperture.
This does not guarantee that the predefined number of loose products will be present in the package, and therefore it does not guarantee a precise metering of the loose products into the package.
In some situations, moreover, the loose products can be positioned in correspondence with the edges defining the collection aperture, and can interfere for example with the closing of the opening/closing member.
In the latter case, intervention is often required by operators, to remove and evacuate the loose products from the conveyor body. However, these interventions entail a loss of the sterile conditions of the chamber, and therefore another sterilization cycle is required to sterilize the loose products in the chamber.
Within the field of transferring loose products pneumatic transporters are also known, used in plants for washing stoppers, an example of which is described in JP-A-2013.94768.
Pneumatic transporters of this type comprise a tubular element, hollow inside and through which the stoppers are made to pass.
The tubular element comprises a plurality of delivery nozzles disposed both longitudinally and angularly distanced along the development of the tubular element.
In particular, the delivery nozzles have delivery apertures disposed inside the tubular element, each of which delivers a stream of gas in a longitudinal direction of the tubular element.
The streams of gas delivered in the tubular element determine a thrust of the stoppers in a longitudinal direction along the tubular element itself.
However, this solution is not able to solve the problem of the unwanted positioning of loose products in dead zones of the tubular element, and therefore is not able to ensure the correct transfer of all the loose products to the desired destination.
There is therefore a need to perfect a device for discharging loose products for a treatment machine that can overcome at least one of the disadvantages of the state of the art.
In particular, one purpose of the present invention is to obtain a device for discharging loose products for a treatment machine that allows correct operations to discharge the loose products from the treatment machine.
Another purpose of the present invention is to obtain a device for discharging loose products that is reliable and accurate.
Another purpose of the present invention is to obtain a device for discharging loose products that limits, and even eliminates, control and maintenance interventions by operators.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.